Mechanical speaking-telegraph



A.M. ROSEBRUGH.

I MECHANICAL SPEAKING TELEGRAPH. No. 270,848. Patented Jan. 16,1883.

lillplllnl l WITNESSES INVENTOR UNITED STATES PATENT OFFICE.

ABNER M. ROSEBRUGH, OF TORONTO, ONTARIO, OANADA, ASSIGNOR TO WILLIAM HUBBARD, OF ELGIN, ILLINOIS.

MECHANICAL SPEAKING-TELEGRAPH.

SPECIFICATION forming part of Letters Patent No. 270,848, dated January 16,- 1883.

Application filed January 20, 1879.

To all whom it may concern Be it known that I, ABNER. MULHOLLAND RosEBRUGH, M. D., of the city of Toronto,

, apertured stem backward from the posteriorplate of the casing of the telephone.

Figure 1 is a side elevation, Fig. 2 is a sectional elevation, and Fig. 3 is an end View, of a mechanical telephone showing my improvement.

A is a casing, B the mouth-piece, O the posterior plate, D posterior projecting stem ortube, E the line, f the diaphragm, g elastic cushions, J aperture of stem, and H an apertured support, for the telephone. By means of this posterior projecting stem or tube the instrument maybe inserted in an orifice of a wall, sash, window-casing, or other support, and it is kept firmly in position by the tension ot'the line. The stem and posterior plate is preferably made of metal and preferably cast in one piece. It is centrally apertured for the passage of the line, and said aperture must be large enough not only to admit of the passage of the line, but also to admit ot'free vibrations. The stem and aperture may be of any convenient shape.

\Vhat I claim as new is-- In a mechanical or acoustic telephone, atube or perforated stem proj cting from the central part of the posterior plate, through which the line passes and by which the instrument is kept in position, substantially as described. A. M. ROSEBRUGH. Witnesses:

CHAS. POTTER, M. M. ROSEBRUGH. 

